Engine



Jan. 29, 1946. A. E; WALDEN 2,393,557

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Patented Jan. 29, 1946 ENGINE Alfred E. Walden, Detroit, Mich., asslgnor to Manufacturing Company, Detroit,

Mich., a corporation of Michigan Application August 19, 1943, Serial No. 499,166

21 Claims.

This invention relates to internal combustion engines and particularly to engines of the type having rotatable valves associated with the cylinders thereof and usually mounted in the cylinder heads of the engines. The present invention has particular although not exclusive application to an internal combustion engine of the kind in which the rotatable valve in the head, preferably although not necessarily of the kind which rotates continuously in one direction, is formed with substantially all or at least the major portion of the combustion chamber and is generally conical or frusto-conical in shape. The combustion chamber within the rotor or rotary valve has an opening at one end leading to the cylinder and a second opening preferably at a side thereof adapted to communicate during operation with an outlet or inlet passage, or both, as the case may be, and the combustible charge within the combustion chamber is fired preferably by spark ignition.

Engines of the foregoing type present the possibility of considerable advantages, long recognized, as compared with conventional engines of the poppet valve type, such as simplification of construction, reduction in weight, and higher speed operation with consequent increase in power output. Many difliculties, however, are presented in the production of a satisfactory engine of this type, one of the most serious being in connection with the ubrication of the rotary valve and oil consumption. It is important that lubricating oil be supplied to the rotary valve and that an adequate oil film be maintained between juxtaposed rubbing surfaces of the valve and the cylinder head during operation. It is also important that the amount of oil consumed during operation of the engine be reduced to a minimum and that lubricating oil not only be delivered in required or controlled amounts to the surfaces needing lubrication but also in such manner as to minimize carbon formation and clogging of oil passages.

Although in the past some attention has been directed to the lubrication of the rotatable valves of engines of the foregoing type or kind, yet I am aware of no instance in which the lubricating oil, especially any excess oil, delivered to the valve for lubricating purposes may be positively carried away from the valve so as to reduce the amount of oil lost by burning, nor any instance in which the valve is lubricated through the medium of a circulating pressure system whereby oil passages are kept clear and a high degree of control of the valve lubrication is achieved.

One of the objects of the present invention is to provide improved means for lubricating the rotatable valve of an internal combustion engine resulting in appreciably less danger of oil passages becoming clogged due to the formation of carbon and hence insuring adequate lubrication which may be relied upon under conditions of sustained operation.

Another object of the invention is to provide an improved lubricating system for the rotatable valve in which the oil delivered to the valve is circulated-and therefore maintained at lower temperature, as a consequence of which less of the oil is subject to burning and the formation of carbon tending to impair operation.

A further object of the invention is to provide a lubricating means for a rotatable valve of the above type of engine which will be more em cient and accurate thereby improving the operation oi th engine and reducing oil consumption.

Another object of the invention is to provide a positive and dependable means for delivering to the rotary valve measured quantities of lubricating oil at predetermined timed intervals.

A further object of the invention is to provide a relatively simple and emcient means ior metering the lubricating oil and intermittently delivering the oil to the rotary valve in metered or predetermined amounts whereby'substantially exact control is maintained of the oil used to lubricate the valve and consequent elimination of excessive oil consumption is achieved.

Still a further object of the invention is to of an engine through the medium of a circulating pressure system whereby greater reliability in the lubrication of the valve is achieved.

Another object of the invention is to provide an improved engine construction in which the rotary valve within th cylinder head or equivalent supporting body is lubricated at predetermined localities by means of an oil groove or grooves either in the head or valve or both and in which the groove or grooves are connected or adapted to communicate with inlet and outlet conduits or passages whereby oil is circulated through the grooves during the lubrication periods.

Other objects of this invention will appear in the following description and appended claims, reference being had to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

Fig. 1 is a fragmentary sectional elevation illustrating a portion of a multi-cylinder engine embodying the present invention.

Fig. 2 is a plan view, partly in section, of a portion of the cylinder head and rotatable valve.

Fig. 3 is a vertical section taken ubstantially through lines 3-3 of Fig. 2 looking in the direction of the arrows.

Fig. 4 is a vertical section taken substantially through lines 4-4 of Fig. 2 looking in the direction of the arrows.

Fig. 5 is a section taken substantially through lines 5-5 of Fig. 3 looking in the direction of the EITOWS.

Fig. 6 is a view showing the development of the urface of the rotatable valve.

Fig. 7 is a view showing the development of the conical surface of the recess in the cylinder head within which the valve is mounted. 4

Fig. 8 is a view showing developments of the rotatable valve surface and the cylinder head conical surface superimposed.

Fig. 9 is a fragmentary view of a portion of Fig. 8 illustrating different relative positions of the valve and cylinder head surfaces.

Fig. 10 is a view somewhat similar to Fig. 4 illustrating a modification.

Fig. 11 is a View somewhat similar to Fig. 4 illustrating a further modification.

Before explaining in detail the present invention it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

In the drawings I have illustrated, by way of example, several embodiments of the invention as applied to an internal combustion engine of the spark-ignition type designed particularly for the power plant of an aircraft. The invention may obviously be utilized in connection with engines for other purposes, such as automotive, marine and industrial engines. For most uses the engine is of the multi-cylinder type. However, for the purposes of simplicity a single cylinder unit of the engine is illustrated in the present embodiment, it being understood that the remaining cylinders of the engine are identical to the structure herein shown and described.

Referring to Fig. 1, the present engine comprises a suitable crankcase 20 within which is mounted a crankshaft 2| supported in bearings according to conventional practice. A cylinder 22 is secured rigidly in the crankcase and has its lower or inner end projectingv thereinto. Mounted to reciprocate within the cylinder is a piston 23 adapted to be connected in the usual manner by a connecting rod 24 to the crankshaft 2i. p

In the present engine the combustion chamber of the cylinder is formed principally within a rotor or rotary valve member 25, this member comprising a frusto-conical body arranged immediately above the piston when at the top of its stroke. The valve 25 is provided at its outer end with a cylindrical stem 26. The rotor 25 fits within a substantially correspondingly shaped frusto-conical cavity 21 in an upper cylinder head member 28.

.The rotor 25 is driven through the medium of the stem 26 which is positively connected to a driving gear in such manner as to permit slight relative axial and radial movement between the driving gear and the rotor. stem 26 has a longitudinal splined connection 23 with a sleeve 30 which in turn has a longitudinal splined or toothed connection 3i at its upper end with a driving gear 32, the gear having a depending cylindrical hub or sleeve 33 interposed between the sleeve 30 and a bearing or bushing 34. The gear 32 has an annular recess 35 at its outer side adapted to receive and house a compression spring 38. This spring is engaged by a retainer 31 which is clamped to the valve stem 26 by means of a nut 38 provided with a shank 38 threaded into a tappedhole in the stem 26. The valve member 25 is formed with a cooling chamber 4| extending entirely around the combustion chamber of the valve member. This cooling chamber is adapted to receive any suitable cooling medium, such for example as metallic sodium, which is sealed into the chamber by means of a screw plug 40 threaded into the tapped hole in the valve stem 26.

From the foregoing it will be seen that the valve 25 may be rotated from the gear 32 through the medium of the splined connections 23 and 3i which permit slight relative axial and radial movement of the valve during operation. The valve is yieldingly held outwardly against the tapered wall 21 of the valve cavity or recess in the head by means of the spring 36. The driving gear 32 is provided with gear teeth 32a meshing with the teeth of a gear 42 driven by a gear 43 secured'to the upper end of a tower shaft 44 extending through a tubular housing 45. Secured to the lower end of the tower shaft is a gear 46 meshing with a gear 4! pinned to the crankshaft 2|. It is important to note that the spring 36 is at all times loaded and held under compression between the retainer 31 and the gear 32 and the spring pressure in an upward direction at all times exceeds the downward pull on the valve caused by the suction or partial vacuum created during the suction stroke of the piston. As a consequence, the spring pressure is sufficient to maintain the valve at all times in proper contact with the conical cavity or recess 21. in the cylinder head, thereby maintaining predetermined clearances between the valve and cylinder head and a constant oil film between the cooperating bearing surfaces thereof.

The rotor 25 is formed with a combustion chamber 48 which preferably forms substantially all of the combustion space at the time of firing when the piston 23 is in its position of maximum compression. The piston is preferably formed with a tapered end 23a which is adapted to project a slight distance into the combustion chamber 48, as shown in Fig. 1, and the bottom of the valve is tapered so as to correspond substantially to the shape of the upper crowned or tapered portion 23a of the piston.

In the particular embodiments herein illustrated it will be seen that the rotor or valve 25 ha a single port 49 in its side communicatin with the combustion chamber 48 and adapted to register in succession with an exhaust conduit 50, an intake conduit 52 and a spark plug at location 5|. In these embodiments, therefore, the valve or rotor 25 is driven at one-half engine or crankshaft speed, the direction of rotation of the valve being indicated by the arrow in Fig. 2. The driving mechanism, above described and shown in the drawings, is illustrative of a suitable mechanism by which one of a plurality Accordingly, the

of rotary valves '25 or a corresponding plurality of cylinders 22 may be driven from the crankshaft 2|.

The spark plug location 5| is in the form of a tapped hole for reception of a spark plug of any suitable type.

The present engine preferably utilizes a fuel injection system, although it will be understood that the invention is not so limited and that a carburetor may be employed for supplying the fuel charge to the combustion chamber 46 when the side port 49 of the valve registers with the intake conduit or passage52. Where a fuel injection system is used, fuel may be injected through the medium of any suitable fuel injector (not shown) into theair stream in the passage or conduit 52 sothat the rotor will be supplied with the proper combustible mixtureat the time of ignition, namely when port 49 of the rotor registers with the spark plug at location 5|.

In addition to the side port 49 the valve or rotor 25 is provided at the bottom or inner end thereof with a centrally located port 53 adapted to communicate with the outer end of the cylinder 22. As previously-stated,- the bottom surface of the rotor surrounding the port 53 is tapered and during operation the valve is normally held outwardly within the tapered or frusto-conical cavity 21 of the cylinder head by the compression spring 36. The cylinder head 28 is formed with a depending internally threaded skirt 29a into which the upper threaded end of the cylinder 22 is adapted to be screwed for attaching the head and cylinder together.

In the present embodiments of the invention the principal bearing loads between the rotor or valve 25 and the head 28 are taken substantially entirely at two localities entirely above and below the side port 49. The valve 25 is provided with an annular relief or recessed area 54 extending around the central or intermediate portion of the valve and having a height preferably corresponding to the height of the side port 49. Although in the present instance the relief area is shown in the valve, it will. be understood that it may be formed in the cylinder head in accordance with the disclosure in copendingapplication Serial No. 495,260. As in said copending application such relief area may be filled with a layer of carbon thereby providing a bearing medium not requiring any direct lubrication.

In accordance with the present invention improved lubricating means is provided for the cooperating bearing surfaces of the valve and cylinder head above and below the relief area 56.

The cylinder head is drilled to provide an oil passage or conduit 55 extending generally parallel to the conical surface of the valve. The upper end of this passage is closed by means of a plug 56. Communicating with the passage 55 is a laterally extending passage or conduit 51 connected by means of a coupling to an. inlet tube or pipe line 58 through which lubricating oil under pressure is directed into the passage 55, as shown by the arrows. Extending from opposite ends of the passage or conduit 55 are ducts 59 and 61 which extend through the wall of the cylinder head and open at the conical face of the valve. The upper or outer smaller end of the valve is provided with an oil groove 69 on its outer surface. This groove is preferably zigzag in form having longitudinally or axially spaced parallel portions 69a and 60b connected by inclined portions We. The groove extends continuously around the upper end of the valve andv the portions 69a are arranged so as to register intermittently or successively with the inlet oil duct 59 during rotation of the valve. Since the lubricating oil in the passage is constantly under predetermined pressure, it will be seen that, during rotatio of the valve, oil will be forced through duct 59 into the oil groove intermittently when the groove portions 60a register with the duct 59. At such time the oil will be forced through the inclined portions 600 into the portions 69b of the groove. Such a condition is shown in Fig. 9. When, however, the portions 60a are out of registry with the duct 59, as shown in Fig. 8, no oil will be delivered from passage 55 to the oil groove 69.

The cylinderhead is also drilled to provide an outlet oil passage or conduit 6|, see Fig. 4, extending nearly the full length of the valve and a shorter passage 62 near the upper end of the valve. These passages BI and 62 open into a chamber 63 extending around the valve stem 26 below the gear 32. Communicating with the oil chamber 63 is an outlet or drain pipe 64 by which the lubricating oil is returnedto the crankcase or other source of supply. Extending from the passages 6| and 62 are outlet oil ducts 65 and 66, respectively, which extend through the wall of the cylinder head and open at the face of the valve. These ducts are adapted to register intermittently with the portions 69?) of the oil groove 60, as illustrated in Fig. 9. Thus, when the inlet oil duct 59 registers with one of the 3 pressure passes through duct 59 into the oil groove 66 through portion 66;: the oil will flow under pressure out of the portions 60b of the oil groove through ducts 65 and 66 and passages BE seen that the amount of oil delivered to the oil groove will depend upon the length of the portions 66a of the oil groove'and the lengthof the portions 66b of the oil groove. The lengths of these portions may be varied to suit lubrication r nish only the required amount.

under pressure, there is little or no possibility of this groove or the ducts 59, 65 and 66 becoming clogged by the formation of carbon.

Referring to Fig. 3, the lower end of the inlet passage 55 communicates with the surface of the valve at the lower end thereof by means of a duct 61. This duct leads into a circumferential oil groove 66 formed on the inner conical surface 21 of the cylinder head. This groove 68 is of predetermined length, determined by lubrication requirements, and the end thereof opposite to the duct 671 communicates with the outlet passage 6! by means of a duct 69. In the preferred construction the groove 68 increases in depth toward the outlet duct 69. From this construction it will be seen that oil under pressure from the passage 55 constantly flows through duct 61 into oil groove 68 and out of this oil groove through duct 69 into the outlet passage 6| and thence to the oil chamber 63. Lubricating oil is thus circulated under pressure through the oil groove it, thus preventing this groove from clogging on account of the formation of carbon. Since the lower conical surface of the valve faces the groove .8, lubricating oil will be delivered thereto and the amount thus supplied depends upon the length of this groove.

In the embodiment illustrated in Fig. the principal bearing loads, which are taken above and below the circumferential area measured by the height of. the side port 49, are transmitted from the valve to the cylinder head by means of upper and lower frusto-conical bearing rings II and 12. These rings are preferably floating rings and are mounted in generally correspondingly shaped recesses in the valve and head. However, in some instances it may be found desirable to make the rings stationary or fixed in their respective recesses in the valve and head. The upper ring Ii is mounted in a recess in the valve and the lower ring 12 is mounted in a recess in the head. This construction may be similar to disclosures in Patent Number 2,374,190 of --April 24, 1945, and Patent Number 2,374,250 of April 24, 1945. The inlet oil duct 59 is adapted to register with a circumferential slot or groove extending through the bearing ring II and registering with the portions 60a of the oil groove 60, the slotor groove in the ring 1i corresponding in length to the length of the oil groove portions 60a. The inlet duct 61 is also adapted to register with a circumferential slot or groove extending through the ring 12, corresponding in length to the oil groove 68, by means of which oil is supplied under pressure to the lower bearing surface of the valve.

The embodiment illustrated in Fig. 11 corresponds substantially to that illustrated in Figs. 1 to 9 inclusive with the exception that the lower oil groove 68 in the cylinder head is of zigzag construction as shown at 10. One end of this groove communicates with the passage 55 by means of oil duct 61 and the opposite end of the groove communicates with passage Bi by means 01' oil duct 69.

I claim:

1. In an internal combustion engine, a rotatable valve, and a body within which said valve rotates, said body having an oil inlet conduit and an oil outlet conduit, and said valve having a zig-zag oil groove comprising a portion ,efiecting communication between said conduits and a portion in non-communicating relation thereto. 1

2. In an internal combustion engine, a rotatabl .valve, and a body within which said valve rotates and having a conduit for directing oil to the valve, said valve havingan oil groove comprising connected portions, one portion arranged for communication with said conduit and another portion arranged in non-communicating relation to the conduit during rotation of the valve, and a conduit for conveying oil from the valve and arranged for communication with said groove only when said first conduit is in communication therewith.

3. In an internal combustion engine, a rotatable valve, and a body within which said valve rotates and having a conduit for directing oil-to the valve, said valve having a zig-zag oil groove including portions intermittently communicating with said conduit.

4. In an internal combustion engine having'a cylinder, a body, a rotatable valve in the body associated with said cylinder, means in said body for delivering lubricating oil to the valve, and an oil groove extending around the valve having portions intermittently communicating with said means.

5. In an internal combustion engine having a cylinder, a body, a rotatable valve in the body associated with said cylinder, means in said body for delivering lubricating oil to the valve and a zig-zag oil groove extending continuously around the valve for intermittently establishing communication with said means.

6. In an internal combustion engine having a cylinder, 8. body, a rotatable valve in the body associated with said cylinder, means in said body for delivering lubricating oil to the valve, an oil groove extending around the valve having portions intermittently communicating with said means, and conduit means in said body for carrying lubricating oil away from said valve when said oil groove is in communication with said first named means.

7. In an internal combustion engine having a cylinder, a body, a rotatable valve in said body associated with the cylinder, said body having an oil groove opening toward the valve with portions thereof spaced circumferentially with respect to the valve.

8. In an internal combustion engine having a cylinder, a body, a rotatable valve in said body associated with the cylinder, said body having an oil groove opening toward the valve with portions thereof spaced circumferentially with respect to the valve, and inlet and outlet oil passages communicating with said groove at separated points.

9. In an internal combustion engine having a r cylinder, a cylinder head, a rotatable valve in said head, an oil inlet conduit in said head, an oil outlet conduit in the head for directing lubricating oil away from the valve, an oil passage in the valve intermittently connecting said conduits, and an oil passage in the head constantly communicating with said conduits.

10. In an internal combustion engine having a cylinder and a'cylinder head, a rotatable valve in the head having a combustion chamber, a side port leading therefrom and a bottom port communicating with the cylinder, said valve and head having a circumferential relief area in the height of said side port, means for introducing lubricating oil to the valve at points above and below said relief area, and conduit means for carrying oif lubricating oil from points also located above and below said area and spaced from said first named points.

11. In an internal combustion engine, a rotatable valve, and a body within which said valve rotates, said body having an oil inlet conduit and an oil outlet conduit, and said valve having a continuous circumferential oil groove including a portion eflecting communication between said conduits and a portion in non-communicating re lation thereto.

12. In an internal combustion engine, a cylinder, a cylinder head, a rotatable generally frusto-conical valve in said head having a combustion chamber and a port in the side wall thereof communicating with said chamber, said valve also having a port at the inner end thereof in constant communication with said cylinder, an arcuately extending oil groove in said head opening toward said valve around only a part of the circumference thereof, and inlet and outlet conduits in the head communicating at spaced points with said groove.

13. In an internal combustion engine, a cylinder, a cylinder head, a rotatable generally frustoconical valve in said head having a combustion chamber and a port in the side wall thereof communicating with said chamber, said valve also having a port at the inner end thereof in constant communication with said cylinder, an arcuately extending oil groove in said head opening towardsaid valve around only a, part of the circumfer-.

ence thereof, and inlet and outlet conduits in the head communicating at spaced points with said groove, said oil groove being positioned at the opposite side of the head fromsaid valve side port when the valve is in firing position.

14. In an internal combustion engine, a rotatable valve and a body within which said valve rotates, said body having an arcuately extending oil groove of varying depth opening toward the valve around only a part of the circumference thereof, and inlet and outlet conduits in the head communicating at spaced points with said groove.

15. In an internal combustion engine, a retatable valve and a body within which said valve rotates, said body having an arcuately extending oil groove opening toward the valve around only a part of the circumference thereof, and inlet and outlet conduits in the head communicating at spaced points with said groove, said valve having a combustion chamber and a side port communieating with said chamber, and said oil groove being positioned remote from said side port when the valve is in firing position.

16. In an internal combustion engine, a ro-.

tatable valve and a body within which said valve rotates, said valve having a combustion chamber and a side port communicating with said chamber, two spaced oil conduits inthe head extending along the side of the valve, oil ducts leading from each conduit to the valve, and oil grooves at opposite ends of the valve efiecting communioil ducts leading from the two oil 18. In an internal combustion engine, a rotatable valve and a body within which said valve rotates, said valve having a combustion chamber and a side port communicating with said chamber, two oil conduits in the-head spaced circum ferentially of the valve, oil ducts leading from each conduit to the valve at points unexposed to said side port during operation, and oil grooves at opposite ends of the valve efiecting communi! cation between oil ducts leading from the two oil conduits, one of said oil grooves extending circumferentially around the valve and the other only part way therearound.

19. In an internal combustion engine, a rotatable valve and a body within which said valve rotates, two circumferentially spaced inlet and outlet oil conduits in the head having oil ducts leading to side bearing surfaces of the valve, and an annularly extending oil groove in the valve extending at least part way around the valve and adapted to register intermittently with said ducts during rotation of Y the valve to permit a directional flow of oilunder pressure through the groove at spaced intervals.

20. In an internal combustion engine, a rotatable valve and a body within which said valve rotates, said valve having a combustion chamber and a side port communicating with said chamber, two inlet and outlet oil conduits in the head spaced circumferentially of the valve, oil ducts leading from each conduit to bearing surfaces of the valve at points unexposed to said side port during operation, and oil grooves at opposite ends of the valve at the locality of said bearing surfaces eifecting communication between certain of said oil ducts.

21'. In an internal combustion engine, a rotatable valve and a body within which said valve rotates, said valvehaving a combustion chamber and a side port communicating with said chamber, two inlet and outlet oil conduits in the head spaced circumferentially of the valve, oil ducts leading from each conduit to bearing surfaces of the valve at points unexposed to said side port during operation, and oil grooves at opposite ends of the valve at the locality of said bearing surfaces efiecting communication between certain of said oil ducts, one of said oil grooves extending circumferentially around the valve and the other only part way therearound.

' ALFRED E. WALDEN. 

